Missfire

[Matt_Fezzy]

Anyone else getting a missfire on the cold mornings?

Have taken it to the garage and the ECU fault is the oxygen sensor.

They think it may be because of the de cat + cold mornings. Its fine when the car gets up to temp. But before it does it missfires quite low down the revs.

I bought and Rs tuner now to have a play with the ECU as I keep gettin oxygen sensor faults even when the car doesnt missfire. Do you think i should get two new sensors?

 

[gogsie]

I have something similar but mine is more a loss of power feels like fuel starvation or similar, I also have a decat and the problem dissapears when the car is hot. Let me know if you find out anything.

P.s i fitted a new lambda when the decat was fitted.

 

[Matt_Fezzy]

I have something similar but mine is more a loss of power feels like fuel starvation or similar, I also have a decat and the problem dissapears when the car is hot. Let me know if you find out anything.

P.s i fitted a new lambda when the decat was fitted.

Yeah thats pretty much what I have got. I will keep you posted if I find something

 

[gogsie]

Cheers

 

[Vicky.]

Yeah I'm getting the exact same thing and I have a decat too. It's getting on my nerves so I want to put the cat back on but will miss the noise. Still debating...so post up if you get it sorted

 

[Poopensharten]

Remember guys and gals that a missfire can be caused be a few things...

If a car has faulty sparkplugs/HT leads that can cause a mis fire, also, a faulty injector could cause it to seem very reserved and not pull aswell as it should.

Also check the coil packs aswell

 

[gogsie]

Any way of diy checking the injectors?.

I have new leads and plugs, Not checked the coil though.

 

[Vicky.]

Remember guys and gals that a missfire can be caused be a few things...

If a car has faulty sparkplugs/HT leads that can cause a mis fire, also, a faulty injector could cause it to seem very reserved and not pull aswell as it should.

Also check the coil packs aswell

Yeah it's one of those things that's a pain to get sorted, have had the coilpacks changed as had a misfire before.

I need to see about getting a new crankshaft sensor from Renault aswell so dont know if that would affect it as at the moment it idles a bit odd but new sensor should sort that.

Im just assuming its the decat as its started doing it ever since I had it fitted.

 

[Da]

A decat will alter your idle as the post-cat sensor will be getting incorrect readings.

 

[Matt_Fezzy]

Yeah like I say the diagnostics was saying the oxygen sensors are at fault. So we think it will have something to do with the fuel because of the de cat and the cold. No faults came from the coil pack or that area. I feel a bit better now a few people are having the same problem. Hopefuly will have it sorted soon enough.

 

[gogsie]

Keep us posted if you get a result.

 

[Alexjfinch]

I found the other morning that when I started my car and raised the engine revs to 1900rpm the car had an awful missfire that appeared to go away once warmed up.

Yet this morning it didn't do it.

Mines completely standard with a new set of plugs, I'm quite unsure whats wrong with it.

 

[sideways danny]

A decat will alter your idle as the post-cat sensor will be getting incorrect readings.

wrong

post cat lambda makes no changes

 

[Matt_Fezzy]

Mine has been fine the last two mornings. But it has been slightly warmer. Still annoying if it does happen. Have a go with the tuner this weekend

 

[Dunn]

im on about my 6th clio an they all hated cold mornings lol
just let em warm up
the decat does make it a bit worse but not much jus cos you can hear it more clearly
i always leave mine running for 5 mins before i drive it

 

[Da]

wrong

post cat lambda makes no changes

So is it purely an emissinons sensor? It has no bearing on how the car runs?

 

[minisuper666]

wrong

post cat lambda makes no changes

+ a cold startup will not be taking the lamda in consideration.